Research On Abrasive Water Jet Cutting Technology Of Open Integral Blade Disk

Abrasive water jet processing technology is a cold energy beam processing method,which has more significant advantages such as no processing heat impact,high processing flexibility and high efficiency compared to traditional mechanical processing.Compared with the traditional separate impeller connected by mortise and tenon groove,the monolithic impeller is designed to reduce the gas loss rate and improve the thrust-to-weight ratio of the engine by designing the blade and hub as a whole.However,the manufacturing process of monobloc impeller is more difficult,and nowadays,it is mostly machined by milling.As the material of the integral impeller is mostly titanium alloy or high-temperature alloy and other typical difficult-to-machine metal materials,the tool wear is more serious during the machining process,while the machining cycle is longer,the machining efficiency is lower and the machining cost is higher.Up to ninety percent of the material needs to be removed during the rough machining of the integral impeller,and abrasive water jet machining technology has great potential for the machining of integral impellers.This study was first carried out to investigate the effective and ultimate cutting lengths of abrasive water jets.The cutting experiments were conducted to study the effect of each process parameter on the ultimate cutting depth under the conditions of high overall pressure level and to understand the ultimate cutting capability of the equipment used.Then the cutting experiments were carried out on TC4 by response surface experiments,and the mathematical models of effective cutting length and ultimate cutting length of abrasive water jet were obtained,on which the mathematical model of cutting length of abrasive water jet was established to lay the foundation for the discrimination of process accessibility.The effects of jet pressure,cutting traverse velocity and abrasive flow rate of abrasive water jets at different parameter levels on the depth of cut of three materials,45 gauge steel,316 stainless steel and titanium alloy,were investigated using LS-DYNA analysis software,coupled with SPH and FEM,to analyze the pattern of material removal from an energy perspective.Based on the study of the effective cutting length of abrasive water jets,the process accessibility of the abrasive water jet cutting the open integral blade disk was judged,and three types of accessibility were defined:unreachable,semi-processable,and fully processable.Based on the machinability and machining allowance,a straight surface bias is applied to the blade machining surface to construct a machinable straight surface for the jet beam,and the machining trajectory of the jet beam is obtained for the open integral impeller.Based on machining trajectory planning,cutting process experiments were conducted for open integral leaf discs,and the time required for cutting to remove individual interleaf passages was counted,with higher efficiency compared to milling processing,while the defects of the cut blades and the reasons for their appearance were analyzed,and cutting process optimization solutions were proposed.